Examine source code of IBM Salesforce Extras

{
  "manifest_version": 2,
  "name": "IBM Salesforce Extras",
  "description": "IBM Salesforce Extras for Support",
  "version": "2.4.1",
  "icons": {
    "48": "icon-48.png"
  },
  "browser_action": {
    "default_icon": "icon-48.png",
    "default_title": "IBM Salesforce Extras",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "permissions": [
    "tabs",
    "activeTab",
    "webNavigation",
    "clipboardWrite",
    "storage",
    "https://*.force.com/*",
    "https://*.visualforce.com/*"
  ],
  "background": {
    "scripts": [
      "lib/jquery-3.3.1.min.js",
      "background-mv2.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.force.com/*"
      ],
      "js": [
        "mainextras.js",
        "lib/jquery-3.3.1.min.js"
      ],
      "css": [
        "lib/toastr.min.css",
        "styles.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2a5d274b-808c-4bcd-90f1-fd3f1dac75c5}"
    }
  }
}